Habits

Yellow Sac Spider

Adult Yellow Sac spiders can be seen from April through November. They emerge at night to look for food. They drop to the floor to seek cover when disturbed.

They are likely to enter homes during early Autumn when their outdoor food supply decreases.

Appearance

Pale in colour, abdomen can be yellow or beige with a faint dark stripe running lengthwise.

1/4 to 3/8 inches long.

4 pairs of legs, the 1st pair longer than the 4th.

Eight similarly-sized dark eyes arranged in two horizontal rows.

Life cycle and habits of a Yellow Sac Spider

Life Cycle

A female produces around 5 egg sacs each with 30 to 48 eggs. The female may produce several egg masses during her lifetime.

Eggs are laid in autumn.

Spiderlings emerge the following spring.

Approximately 30% of adult males get eaten by females after mating.

Habits

Feeding - usually small insects.

Location – They build a silken tube or sac (instead of a web) in a protected area which is used as their daytime retreat.

Externally this can be within a leaf or under logs; Indoors this can be or at the junction of a wall and ceiling or behind pictures and shelves. They are normally outdoor spiders, but will set-up indoors if there are small insects available and are found on walls and in corners close to the ceiling, they drop from ceilings on silk threads.

Habits

Locations - They prefer secluded, dark, undisturbed sites indoors or outdoors. Indoors, they may be found in attics, basements, closets, ductwork, in storage boxes, shoes or behind furniture. Externally they may be found in barns, storage sheds, garages, under logs, loose stones and stacks of lumber.

Feeding - They prefer dead insects.

They can survive about 6 months without food or water.

Visibility - The sac serves as the spider's daytime retreat. They tend to look for food at night.